Detergent milled bar and process of preparing same



May 2, 1961 J, BLINKA ETAL 2,982,735

DETERGENT MILLED BAR AND PROCESS OF PREPARING SAME Filed Sept 8, 1955 BI00 I00 y... .l

A E L; 75 75 l LU O O m '5 -7 5 a X 3 5o 50 V Q g y 2 U 25 UJ 0 25 v '1DJ o I 0 4o 60 so aoo TEMPERATURE C wafim,afi M16. 1' 60mm United StatesPatent DETERGENT MILLED BAR AND PROCESS OF PREPARING SAME Joseph Blinkaand Preston W. Grounds, IL, Cincinnati, Ohio, assignors to The Procter &Gamble Company, Cincinnati, Ohio, a corporation of Ohio Filed Sept. 8,19ss,'ser. No. 533,081

12 Claims. or. 252-121 nary toilet soap, having what is referred to'inthe art as a draggy feel. Furthermore, bars of this type usually havetendency to smear or develop a slimy outer surface when left in contactwith water, which detracts markedly from the appearance of thebar,'nec'essitates frequent cleaning of the soap dish, and results inexcessive waste.

We have discovered that these and other defects of starch filleddetergent bars may be overcome, and the characteristics of such barsotherwise improved, if the starch be properly gelatinized as hereinafterdescribed.

Further objects and features of the invention willbe apparent from thefollowing description taken in connection with the accompanying drawing,in which:

Figure 1 is a graphical representation of the effect of temperature ongelatinization of certain starches, and

Figures 2 and 3 are photomicrographs of compositions containing starchin normal and gelatinized form, respectively.

If starch is suspended in water and heated, a gradual taking up of Water(gelatinization) occurs. This is described in Radley, Starch and ItsDerivatives, 2d ed., vol. 1, pages 89 and 90. Figure 1, taken-from thepublication by Radley, shows how the gelatinization of potato and cornstarch proceeds We prefer to determine the extent of gelatinization bymeans of a microscope fitted with cross Nicol prisms. The ungelatinizedparticles show a birefringence when thus viewed. In the practice of thepresent invention, we prefer to gelatinize to the point B, Fig. 1, whereall of the anisotropy as shown by birefringence has disappeared. Asstated by Radley in speaking of gelatinization generally, some workersin the field consider the point of gelatinization to be the point A,where anisotropy disappears from the majority, of

the granules, but for use of the gelatinized 'starch in synthetic barformulations, we find the characteristics we desire to be more fullydeveloped if we gelatinize until all anisotropy disappears.

The starch used should be a normal (non-waxy) starch. The amylose{content of these non-waxy starches is reported to be from about 15to'about 25 percent and this type of starch appears necessary fortheattainment of the characteristics we desire. The Waxy starches,containing little or no amylose, do not yield a satisfactory product.

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to use in preparing our product than the untreated 1 starches. Theseoxidized starches may be gelatinized with much less water thanthe'untreated starch; normally a ratio of 4 parts of water to one ofoxidized starch is suflicient in the presence of synthetic detergentsand soaps, both of which are retarders of gelatinization; The oxidizedstarches are readily available from starch manufacturers I Thecompositions of our invention contain at least 10% of sodium soaps offatty acids, preferably from talloW or coconut oil. These may be addedin whole or in part to the aqueous solution and dispersion used togelatinize the starch, butit is conducive to, better appearance if thesesodium soaps are added after the starch preparation has been dried.

Our preferred method for gelatinizing the starch is to add to a mixer,commonly called a crutcher in the soap industry, enough hot water sothat the mix will contain from about 55 to about of water when allingredients including the synthetic detergent that are to go into thecrutcher are placed therein. The synthetic detergent or detergents andany other ingredients that it is desirable to add at this time are thenadded and dispersed in the water. The oxidized starch is then added, andthoroughly dispersed with an auxiliary high speed mixer. On a pilotplant scale this may be accomplished with a hand-held, motor driven,propeller type mixer.

The crutcher is then run with the regular agitation. The mix is, rolldriedand the completion of the gelatinization of the starch takes placeon the rolls. The temperature required to efiect the completion ofgelatiniza tion is achieved when the rolls are supplied with steam atabout 60 lbs. pressure, and will vary with different starches. Asindicated in Figure 1 of the drawing, gelatinization of cornstarch maybe effected at about C. and of potato starch at about C. Time is, ofcourse, a factor and, generally speaking, lower temperatures may beemployed when the starch is heated for a longer period of time.

7 Figure 2 shows the appearance of oxidized starch in a crutcher mix.The dark cross dividing each granule into four parts is typical of thebirefringence shown by ungelatinized starches. Figure 3 shows thecomplete disappearance of birefringence in the finished bar.

The dried crutcher mix may be milled, extruded .and stamped inconventional soap making equipment. If the sodium soap was not added tothe crutcherit should be added before milling. -The sodium soap may beadded as dried flakes or pellets, or part of it may be added asneatso'ap containing about "30% water if the dried mix dried mixin the'amalgarnatore -a device for mixing materials with dried soaps. Anamalgamator is commonly used to mix perfumeand' coloring matter withsoapsbefore milling. In smallscalework, suchas some-dcscribed hereafter,the amalgamator may be dispensed The normal starch maybe brought-to thedesired conditionin a number of waysf It may be suspended in water andheated. This has the disadvantage of introducing a large amount of=waterinto the composition because normal starch willnot-gelatinizeunlesssuspended .inmore than about ,15 times its weight ofwater.

with and the mixing achieved by an extra pass thru'thev milling rolls. IThe synthetic detergents that may be employed ilr-the practice of theinvention are the normally solid synthetics,

commonly referred to as anionic organic sulfuric reaction products.Cationic detergents are not suitable, being incompatible with soap, andnonionic detergents are commonly either liquid or pasty,and ,areof tennonlathering,

. of ethylene oxide.

20 minutes.

limited.

Alkyl glyceryl ether sodium sulfonate in which the alkyl is at least 50%dodecyl.

The alkyl sulfates, typified by sodium dodecyl sulfate.

The alkyl monoglyceride sulfates, such as coconut monoglyceride sodiumsulfate. (These are preferably not used with alkaline builders.)

The alkyl monoglycol sulfates, such as coconut ethylene monoglycolsodium sulfate.

The alkyl monoglyceryl sulfonates, such as coconut monoglycerol sodiumsulfonates.

The isethionates-RCOOC H SO Nawhere the RC preferably represents acylradicals in a mixture of fatty acids from oils of the coconut group; forexample coconut fatty acids esterified with isethionic acid andneutralized with sodium hydroxide.

By oils of the coconut group we mean to.designate vegetable seed or nutoil having at least 50% by weight of the combined fatty acids as lauricand/or myristic. Practically all of these are derived from nuts of thepalm family such as coconut oil, palm kernel oil, tucum kernel, andbabassu nut oil.

The methyl taurines RCONCH C H SO Na, where RC O preferably representsacyl radicals in a mixture of fatty acids from oils of the coconutgroup, e.g. sodium salt of coconut acid amide of N methyl taurine.

The sulfo acetates ROOCCH SO Na, where R preferably represents alkylradicals contained in fatty alcohols derived from an oil of the coconutgroup specifically the sodium salt of coconut sulfo acetate.

Detergents made by sulfating and neutralizing the compounds made byreacting a coconut fatty amine with hydroxy acetic acid.

The alkyl benzene sulfonates, where the alkyl is a keryl or apolypropylene of C9 to C are satisfactory physically, if their tendencyto exhibit a sticky feel is'not objectionable under their circumstancesof use.

There may be used 'with the normally solid anionic detergents listedabove, a limited amount of pasty or even liquid synthetics such as thenonionic synthetics.

In the following examples the quantities are given on the pure basis,that is, water and sodium chloride and sulfates have been subtractedfrom the gross weights used.

Example 1.-700 ml. of hot Water were added to a 1000 gram crutcher. Tothis was added 45 grams of sodiumsalt of middletcut coconut alcoholsulfate containing about'65% C alcohol and 21 grams of the Sulfated andsodium neutralized reaction product of lmole of the same middle cutcoconut alcohol and three moles 30 grams of. sodium soap of 80% tallow,20% coconut oil was then added and 60 grams of sodium coconutoil soap..After these were dispersed,

there was added 18 grams of sodium tripolyphosphate and this wasdissolved. Then there was added 103 grams of Hercules No. sizing starch(oxidized) made by Corn Products Refining Co.; the starch was dispersedby high speed agitation and mixing was continued for about Thetemperature was about 150 F. during this mixing. The mix was roll driedon a roll heated with steam at "about lbsl-steam pressure at the rate of1 lb. of dried product iper hour per square foot of .roll and examinedforungelatinized starch. No birefringence was noted. The mix was milled,extruded from a small plodder and stampedinto 80 gram bars. The finishedbar contained about 1% "of sodium chloride and sodium sulfate and hadamoisturecontent'of 12%.

These bars were good in lather and excellent in resistance to smear whensoaked injwater overnight. The smear test was made by'cutting 'ofi'the'stamped fac'eof a 7 containing about C alcohols.

4 bar to provide a flat surface. The bar was then soaked 16 hours in 70'water. The bar was weighed and then the soft smeary cut surface wipedoff with the full force of the forefinger. The bar was then reweighed.The loss in weight compared to that of a similar bar of soap ordetergent known to be satisfactory when tested in the same manner, is ameasure of smear.

Example 2.This composition was similar to Example 1, using the sameingredients, the synthetic detergents being increased over Example 1 andthe starch being correspondingly decreased. The preparation was carriedout exactly like Example 1, except for the change in proportions. Thefinal product had the compositiondry basis:

. Percent Sodium middle cut coconut alkyl sulfate 20 Sodium salt of thesulfated product of reacting 3 moles of ethylene oxide with 1 mole ofmiddle The final bar had 13% moisture. This bar lathered as well as thatof Example 1, and was practically the same in smear when soakedovernight in water.

The sodium middle cut coconut alkyl sulfate in this example may bereplaced by sodium alkyl benzene sulfonate where the alkyl ispolypropylene averaging about 12 carbons in the radical. The bar withalkyl benzene sulfonate performs as well as the one with coconut alkylsulfate but it has a slightly sticky feel to the hands.

Example 3.-This was prepared similarly to Example 1. The finishedproduct analysis, dry basis was Making parts.

To these 100 parts were added on the milling rolls 3.5 parts of middlecut coconut alcohol. The stamped bar contained 12.2% of water. Thecoconut alcohol, a suds builder, improved the latherso that it wasslightly better than that of Example 2. The overnight smear was almostthe same as that of Example 2.

Example 4.'About 650 ml. of hot water at about 200 F. was added to a1000 gram crutcher. To this was added 45 grams of sodium middle cutalkyl sulfate There was then added 9 grams of the sodium'salt of thesulfated reaction product of 3 moles ofethylene oxide to 1 mole of fattyalcohol made from tallow. After these were well dispersed, there wasadded 103.5 grams of Hercules #55 sizing starch made by Corn ProductsRefining Co. The starch was dispersed with rapid agitation and thenheated for about 20 minutes at about F. The mix was roll dried, at about60 lbs. steam pressure on the rolls at the. rate of one pound of driedproduct per square foot,

of the 106v" mi'mt of alkyl sulfatepthis example did not lather quite aswell as the product of Example 3, and the overnight smear was betterthanthat of Example 3, showing that the properly gelatinized starch producesa bar that will hold together when soaked in 70 water for 16 hours. Abar with ungelatinized starch for example will lose in an overnightsmear test, about twice asmuch weight as the same formula made into abar with gelatinized starch.

Example 5 .There was added to a 1000 gram crutcher about 650ml..of hotwater at about 200 F. To this there was added 45' gramsof sodium salt ofmiddle cut fatty alcohol sulfate. To this was added 15 grams of sodiumsalt of the sulfated reaction product of 10.moles of ethylene oxide to 1mole of tallow alcohol and 11.4 grams of sodium coconut oil soap. Therewas then added 45 grams of sodium tripolyphosphate. These were dispersedby mixing and there was added 84 grams of Hercules #55 sizing starch.The temperature had dropped to about 150 F., but this was enough torequire rapid agitation to prevent the starch from gelatinizing inlumps. After the starch was well dispersed, the normal agitation of thecrutcher was restored and the mixing continued for about 20 minutes. Themix was roll dried at about 60 lb. per square inch steam pressure in therolls, at the. rate of one pound of dried product per square foot ofroll per hour. This was enough to complete the gelatinization'ofthe-:starchj There was added on the mills- 78.6 grams of sodium soap of80% tallow, 20% coconut oiland 7.5 grams of middle cut coconut oil fattyalcohol. After milling, the bars were extruded and stamped. The barscontained l-8%' moisture. The bars were excellent in lather, butsuperior in resistance to smear, upon being soaked overnightin water, tothose made with ungelatinized starch.

Example 6.-This was prepared like Example 5, but the proportions weredifferent. The finished bar cont i d I I Sodium salt .of middle cutcoconut alcoholsulfate parts by weight 20 Sodium salt of the sulfatedreaction product of '3 moles of ethylene oxide to S1 mole of tallowalparts 6.5

cohol Sodium soap of 80% tallow, 20% coconut oil parts 18 Sodium soap ofcoconut oil do 12 Sodium -tripolyphosphate do 3 15 Salts andmiscellaneous do 5.8 Starch (Hercules #55) don 20.2 Middle cut fattyalcohol do 2.5 Moisture o 13.8

This bar lathered well, and was satisfactory in smear tests.

Example 7.In this example parts are shown by weight.

20 parts sodium alkyl glyceryl ether sulfonate (middle cut coconutalkyl) 1 parts sodium soap of 80% tallow, 20% coconut oil parts sodiumcoconut oil soap 10 parts calcium hydrated soap of 80% tallow,

coconut oil parts oxidized starch 10 parts water 10 parts miscellaneoussalts.

The sodium alkyl glyceryl ether sulfonate is dissolved in enough waterto constitute 60 to, 75% final mixture in a crutcher. The 80% tallow,20% coconut soap to be made into calcium soap is then dissolved in thecrutcher. The equivalent amount of calcium'chloride is added andstirring continued until dispersion. occurs. is then added and dispersedwith high speed agitation. After dispersion, the agitator is run atnormalspced until a good mix is obtained. The crutcher mix is rolldried; The sodium soap of 80% tallow, 20% coconut oil is added aspellets and the sodium coconut soap as kettle soap to the amalgamator.After mixing, the lot is milled, plodded, and stamped. The hand latherwas satisfactory.

. In place of calcium chloride, magnesium sulfate in equivalent amountsstoichiometrically may be used. If it is desired to produce a mixture ofcalcium and magnesium soaps the chlorides of calcium and magnesiumshould be used to avoid the formation of relatively insoluble calciumsulfate.

The sodium salt of the coconut ester of isethionic acid may be used inplace of the alkyl glyceryl ether sulfonate in the formula of Example 7and will produce a bar of equivalent performance.

While these examples contain synthetic detergents at the 20% level, itwill be understood that the synthetic detergent may vary between 15 and40% depending upon the qualities desired in a bar, and the sudsing powerof the synthetic detergent used. a

The detergent compositions described above are not limited to theparticular detergents described. The synthetic detergents describedabove in the enumeration of normally solid syntheticscan besubstituted'for detergents used in the above examplesv withsubstantially the same results.

We have prepared bars with as little as 15% starch as the only inertbinder-filler and find them satisfactory, however the lowering of thestarch requires. the increasing of the soap or the anionic syntheticdetergent or both. Increasing the soap increases the tendency to curd inhard water, and increasing the synthetic adds to the cost, with noimprovement in performance. 15% of starch is about the lower limit inwhich starch is useful.

The upper limit is set by the fact that about 25% of active (synthcticdetergent plus soluble soap) is the minimum for effective performance'There is usually about a'minimum of 5% of miscellaneous inorganic salts,so the upper limit for starch in a bar is about 70%, although most ofour compositions will be in the range of 15 to 45%.

The soluble soap is a desirable ingredient in a bar containing anionicsynthetic detergent and starch. The soluble soap will normally. beprincipally a sodium soap of coconut oil type or a sodium soap of tallowand coconut oil type. When the anionic synthetic detergentlathers'slowly as it is used, coconut soap is preferred -as..it acts .tospeed up lathering. vThe-soluble soap will normally constitute 10 to 35%ofour compositions. The. soluble soap may be all tallow .soap if speedof lathering is not a primary objective. The sum of the synthetic andsoda soap will normally be not more The synthetic bar containingproperly gelatinized starch may be prepared by spray drying a detergent-The starch I starch crutcher mix instead of roll drying. When this isdone, it is desirable to pass the crutcher mix thru a process stepinvolving vigorous agitation and disintegration, before spray drying.The period of heating in a spray tower is short as compared to rolldrying and the gelatinization and rupturing cannot be easily carried outin the crutcher alone, because of the retarding effect ofthe soap andsynthetic upon gelatinizing and rupturing. A suitable agitation anddisintegration may be achieved by passing the crutcher mix thru ahomogenizing valve at 3000 p.s.i., before spraying into the dryingtower.

Another method of gelatinizing the starch is to precook it before mixingwith the detergents. The oxidized starches are the most useful in thisprocedure as they can be cooked with a water to starch ratio as low as 27 to 1, although a ratio of 4 to'l 'ispreferred in the pres ence-"ofsynthetic detergents which retard gelatinization, whereas untreated cornstarch will require a ratio of about 15 to 1.

Theprecooking of oxidized starch must be done with good agitation toprevent lumping. The mixture of the precooked starch and soap-detergentdispersion will have to be quite thoroughly carried out, otherwise,starch will appear in the finished bar as grit.

The moisture content of barscontaining gelatinized starch soluble soapand a synthetic detergent should be controlled between the lower limitfor plasticity and the upper limit for softness. These limits willnormally be between 10 and 15%, although as little as 5% moisture may beused when the anionic sulfonic reaction product used isof awaxy natureand is used at a high level, say 35%.

It will be preceived that starch may be properly gelatinized in a numberof ways for inclusion in a bar containinga synthetic detergent and we donot wish to be limited to the methods herein disclosed. The prin cipalpoint to be observed is that the starch be gelatinized to thedisappearance of anisotropy.

While the invention described and claimed herein resides in the use, asa binder and fi-ller for a detergent bar containing synthetic detergentand soap, of a starch which has been fully gelatinized while theproportionsof synthetic detergent and soap are not critical, the'utilityof the invention is best demonstrated in detergent bars containinganionic synthetic detergent within the range of 15% to 40%, and soap inthe range of 10% to and in which theamount of starch is not less than15% nor more than 70% otthe bar, the percentages being by Weight. soappreferably constitutes between 35% and 60% of the bar and the moisturecontent is preferably not less than 5% andnot more than 15%.

While the soap bar of thepresent invention comprises essentiallydetergents of theolass described Withstarch, it will be appreciatedthatthe incorporation in the bar of commonly used perfumes, organic andinorganic builders iscontemplated as part of. the instant invention.

It will be appreciated that'reference herein to a syn thetic detergentis intended to include mixtures of detergents of difiierent types. I

What is claimed is: Y

'1. A detergent milled bar having a characteristic soaplike feel,comprising 10% to 35% normally solid, watersoluble sodium soap and 15%to 40% of a normally solid anionic synthetic detergent comprising awater.- soluble, alkali metal salt of an organic sulfuric reactionproduct and a gelatinized non-waxy starch, said gelatinized starch beingcharacterized by the disappearance of anisotropy and constituting notless than 15%, nonmore The total amount-of synthetic detergent and than70% of the bar, the sum of said syntheticdetergent and said sodium soapbeing between 25% and 65%.

2. The detergent bar of claim l'in which the gelatinized starch ispresent in the range of 15% to 45%, the sumof'said synthetic detergentand said sodium'soap being between 35% and 3. I The detergent bar'ofclaim. 1' in which the moisture content is not less than 5% and not'morethan 15%.

4. The detergent bar of claim 1 in which the gelatinized starchconstitutes not less than 15%, nor more than45% of the bar.

5.The deter-gent bar of claim 1 in which the'normally solid, watersoluble sodium soap is. of fatty acids selected from the groupconsisting of tallow fatty acids, coconut oil'fatty acids, and mixturesthereof.

6. In-the process of preparing a milled toilet bar consistingessentiallyof 15% to 40% ofa normally'solid synthetic anionic detergent comprisinga water-soluble.

alkali metal salt of anorganic sulfuricreaction product, 15% to 70%gelatinized non-waxy starch and 10% to 35% normally solid, water-solublesodium soap, the sum of saicl'synthetic detergent and said sodium soapbeing between25% 'and the steps which comprise agi: tating anddispersing starch and synthetic detergent in water, the weight of saidwater being vfrom about 2vto about 1'5.times the weight of said starch,and suflicient in amount to permit complete ,gelatinization of saidstarch, heat drying the mixture, effecting substantiallycomplete'gelatinization of the starch to disappearance of anisotropy,milling and extruding the mixture and stamping same into a bar, and atany stage prior to milling and extruding, adding sodium soap to themixture.

- 7; The process. of claim 6 in which said starch is nor mal starch andit is dispersedin about 15 times its weight of water.

"8. .The process of claim;6 inwhich said starch is oxidized starch andit is dispersed in about.2 to about 4 times its weight of water.

9. The process of claim 6 in which the mixture of synthetic detergent,starch and water is roll-dried with the aid of steam at about 60 poundsper square inch pressure 10. The process of claim 6 in-which the sodiumsoap is added to the mixture of water, starchand synthetic detergent.

'11. The process of claim 6 in which the sodium soap is added to the'dried mixture. I

12. The process of "claim 6 in which a portion of the sodium'soapisadded to the mixture of synthetic detergent, starc'h and'water and there'm'aindenof the sodium soap is added to the dried mixture.

'RierencesCited in the file ofithis patent .UNITED STATES PATENTS1,438,169 Hoyt Mar. 23, 1948 2,714,093 'Blumenthal July 26, 1955

1. A DETERGENT MILLED BAR HAVING A CHARACTERISTIC SOAPLIKE FEEL,COMPRISING 10% TO 35% NORMALLY SOLID, WATER, SOLUBLE SODIUM SOAP AND 15%TO 40% OF A NORMALLY SOLID ANIONIC SYNTHETIC DETERGENT COMPRISING AWATERSOLUBLE, ALKALI METAL SALT OF AN ORGANIC SULFURIC REACTION PRODUCTAND A GELATINIZED NON-WAXY STARCH, SAID GELATINIZED STARCH BEINGCHARACTERIZED BY THE DISAPPEARANCE OF ANISOTROPY AND CONSTITUTING NOTLESS THAN 15%, NOR MORE THAN 70% OF THE BAR, THE SUM OF SAID SYNTHETICDETERGENT AND SAID SODIUM SOAP BEING BETWEEN 25% AND 65%.